We investigated post-natal development of the adrenocortical stress-response system in captive American kestrels (Falco sparverius) by measurements of baseline and stress-induced levels of corticosterone at ages 10, 16, 22, and 28 days post-hatching. Baseline levels of corticosterone increased significantly during post-natal development and although chicks aged 10- and 16-days old exhibited com...

Birds respond to environmental changes by modulating their levels of plasma corticosterone, a stress hormone produced by the adrenal glands. Baseline levels of corticosterone and the magnitude of adrenocortical response to acute stress are known to vary seasonally. Photoperiod is one of several potential factors which could affect the seasonal modulation of corticosterone secretion. In this stu...

Production of corticosteroids from the adrenal gland is a multistep process in which corticosterone is enzymatically processed from its precursor cholesterol. The main hormone regulating the production of corticosterone is the proopiomelanocortin (POMC)-derived adrenocorticotropic hormone (ACTH). Adrenals of POMC-deficient (POMC(-/-)) mice do not produce corticosterone either at basal levels or...

Over the last decade, field endocrinologists have explored the efficacy of using plasma corticosterone concentrations of breeding seabirds as an indicator of food availability and predictor of breeding success. However, studies have been predominately confined to adults and the results have been inconsistent. We examined the relationship between the productivity of black-legged kittiwakes (Riss...

Many chemicals and drugs can induce a neuroendocrine stress response that can be immunosuppressive. Mathematical models have been developed that allow prediction of the immunological impact of such stress responses in mice on the basis of exposure to the important stress-related mediator corticosterone. The area under the corticosterone concentration vs. time curve (AUC) has been used as an ind...

Elevated levels of circulating corticosterone commonly occur in response to stressors in wild vertebrates. A rise in corticosterone, usually in animals of subordinate rank, results in a variety of effects on behavior and physiology. Behavioral and physiological responses to short-term increases in corticosterone are well studied. In contrast, the effects of chronic elevated levels of corticoste...

The rodent stress hormone corticosterone changes neuronal activity in a slow and persistent manner through transcriptional regulation. In the rat dorsal hippocampus, corticosterone enhances the amplitude of calcium-dependent potassium currents that cause a lingering slow after-hyperpolarization (sAHP) at the end of depolarizing events. In this study we compared the putative region-dependency of...

Corticosterone is thought to play an important role in food caching and foraging behaviour. However, the direct influence of increased plasma corticosterone on feeding behaviour is still unclear. In this study the effect of increased corticosterone on feeding behaviour in migratory active red-eyed vireos Vireo olivaceus was investigated. We hypothesized that if increased corticosterone levels f...

There is extensive evidence that post-training administration of the adrenocortical hormone corticosterone facilitates memory consolidation processes in a variety of contextual and spatial-dependent learning situations. The present experiments examine whether corticosterone can modulate memory of auditory-cue classical fear conditioning, a learning task that is not contingent on contextual or s...

We investigated possible interactions between melatonin and corticosterone in modulating the reproductive behavior of male red-sided garter snakes (Thamnophis sirtalis parietalis) following spring emergence. We also examined whether melatonin's modulatory actions could be explained by its potential properties as a serotonin receptor antagonist. Exogenous corticosterone significantly reduced cou...